Just Mobile's original Gum battery pack was a big deal when it debuted in 2008, using a simple plastic shell to house one of the most reasonably priced rechargeable iPod batteries around. Since then, the company has gone upscale, introducing the more expensive Gum Plus and Gum Max, which shared a more elegant, MacBook-inspired metal design. Now the company has brought the metal Plus and Max housing to a new version of Gum ($50), which has been upgraded internally as well. Red, black, or silver aluminum versions are available, and Just Mobile includes a fabric drawstring carrying bag in each box.

Still containing a 2,200mAh battery, the new Gum has a 1-Amp output that allows it to charge either an iPhone or an iPod at full speed, up from the iPod-specific 500mA found on its predecessor. It’s bundled with a Micro-USB cable and an adapter that looks a lot like Apple’s own iPhone Micro USB Adapter, letting the same cord connect to itself, a USB port, and Apple’s devices. Simply plug the cord’s small end into Gum’s port to charge it, or flip it around and attach the Dock Connector adapter for use with an iPhone or iPod—an improvement on the original Gum, which didn’t include any Dock Connector cable. However, Just Mobile still doesn’t pack in a wall adapter, so you’ll either have to use your computer or a spare adapter to recharge Gum when it’s depleted.

This edition of Gum is clearly inspired by the more recently introduced aluminum models, but signs of the original design are still evident. It’s about the size of a thick lighter or a pack of gum; compared with Gum Plus, it’s ever so slightly thicker, and not quite as long. Printed on the underside are regulatory information and warnings, along with clear “Input” and “Output” indicators. Flip it over and you’ll find three battery indicator lights and a multipurpose power/remaining charge button; gone is the original version’s on/off switch. If you’ve been following Just Mobile’s most recent 2.1-Amp Gum Plus and Max designs, you may note that the matte cables it was using for those models felt a little bit nicer than the new cable and adapter pieces, which are very Apple-like due to a glossy finish on the connector ends.

We tested Gum’s charging capabilities with both a pair of iPod touches and an iPhone 4S—while charging the iPod touches, it operates at 500mA speed and ran cool to the touch, but became slightly warm when refueling the iPhone at 1A speed. On test one, Gum was able to fully recharge a depleted fourth-generation iPod touch and then provide an extra 55% charge to a second; those results are just about what we’d expect from a 2200mAh battery. With the iPhone 4S, Gum provided one complete charge—better than expected performance. In both instances, the third final LED light stopped flashing when the cell was almost depleted.

When the original Gum came out, it was impressively affordable—plenty of juice for any iPod at a price tag that rivals weren’t matching. The new model comes in at a higher price, but has appropriate industrial design, pack-in, and charging speed improvements to justify the premium. It’s a universally compatible form factor and the performance is laudable: $50 for a full recharge of a current-generation iPhone in an attractive package earns Gum our high recommendation. If you’re in the market for a mid-range, device-agnostic battery accessory, this is an excellent choice.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
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